Study of Genetic Structure of Grain Yield and Some Agro-Morphological Characteristics in Bread Wheat (Triticum aestivum L.) using Diallel Analysis and GGE Biplot Method

In order to investigate grain yield and some of the agro- morphological traits genetical characterization in bread wheat, seven cultivars of wheat including Hamun, Alamut, C-84-12, Gaspard, Ghods, Moghan 1 and Afshar were evaluated in a one-way diallel cross experiment. Parents and hybrids resulting from their one-way dial cross (21 hybrids) during the 2018-2019 crop year were studied in a randomized complete block design with three replications. Analysis of variance related to genotype effect was significant for grain yield, 1000-kenal weight, plant height, peduncle length, spike length, awn length and stem diameter. The general combining ability of Gaspard cultivar was positive and significant for grain yield. Regarding grain yield, the specific combining ability of Hamun × C-84-12, Alamut × Moghan 1, Alamut × Afshar, C-84-12 × Moghan 1 and Gaspard × Ghods were positive and significant and the specific combining ability of Hamun × Afshar and Gaspard × C-84-12 hybrids were negative and significant. GGE biplot showed two heterotic groups, the first group including Hamun, Moghan 1 and Afshar cultivars and the second group including Alamut, C-84-12, Gaspard and Ghods cultivars. Due to the additive effects in the studied plant materials and the cumulative effect on the inheritance of genes to the next generation, it is possible that through selection in the first generations to be useful to increase yield.